There is an ink jet recording apparatus which discharges ink from a plurality of nozzles provided in an ink discharger and lands the ink in a desired position on the recording medium in order to record an image. According to such ink jet recording apparatus, defects in ink discharge from the nozzle results in decrease in image quality of the recorded image. Therefore, conventionally, an examination to detect the defective nozzle in which defects in ink discharge is occurring is periodically performed. As one examination method, there is a method to discharge ink from a plurality of nozzles of the ink discharger onto the recording medium to form a dot and a line corresponding to each nozzle, and analyzing the read data of the dot and the line (for example, patent document 1). According to such method, when the position, interval, size, thickness, and density of the dot or line which is read does not satisfy a predetermined standard, the nozzle corresponding to the dot and the line may be detected as the defective nozzle.